lets break this down:
20 round capacity-probably can't use anyways.
detachable mag-many don't like in hunting guns
kalishnakov action-even if you spend a couple weeks at deer camp you are going to have plenty of opportunities to clean your gun and are not likely going to send more than 200 rounds through it in between cleanings. Even my 11-87(whose action I think is prone to malfunctions and build-up) keeps chugging for 250 very dirty shells flawlessly.
Barel length-less than perfect for many hunting situations.
I fail to see what about a Saiga makes it good for hunting.
For HD, I am with you all the way.
For "homeland defense" or whatever you want to call it, probably the best shotgun available, certainly very close to the top.